Check contrast, quiet zone, density and print size before you print. These are the usual reasons a QR code won’t scan.
Scans well
Contrast 21.0:1 · 25×25 modules (version 2)
Print at least 10 cm (3.9 in) wide.
The design editor runs these checks while you design.
The checker tests your content and colours for the problems that stop codes scanning. It flags contrast under 4:1, a white border narrower than 4 modules, too much content for one code, and a logo without enough error correction. It also gives the smallest print size for your scanning distance. A module is one of the small squares in the code.
“Scans well” means nothing was flagged. “Scannable, with warnings” means it should work, but fix the warnings if the print run is expensive. “Likely to fail” means at least one problem will stop many phones reading it.
Usually low contrast, no white border, too much content for the size, or a logo that covers too much.
Yes, as long as the dots are clearly darker than the background. Aim for a contrast ratio of at least 4:1.
The white border around the code. Scanners use it to find the edges, and the standard is 4 modules wide.
Yes, if the code sits on its own light panel with a white border. Light dots printed straight onto a dark background may fail on older scanners.